#include <stdio.h>

#include <vector>

int main(void)
{
	
    char arr[] = { 0x19, 0x9B };
    short val1 = arr[0] << 8;
    short val2 = (unsigned char)arr[1];
    short val3 = arr[1];
    short value = (arr[0] << 8) + arr[1];


	double t, s;
	scanf("%lg", &t);
    printf("%f", t);
	s = 5 * t * t;
	printf("s=%.2f", s, t);
	printf("Hello world");
	return 0;
}